Density-dependent Factor

Density-dependent Factors

SunlightDue to the older age and species diversity of the temperate forest ecosystems, many grasses and lower lying shrubs have difficulty growing to the breadth of the canopy composed of the taller trees. As a result, little sunlight actually reaches the forest floor, which serves as its own limiting factor. In densely populated ecosystems where the forest canopy soaks up all of the sun, there is little room for new seeds to sprout and turn into mature shrubs and trees unless an older tree dies or loses significant limbs to allow the sunlight to reach the forest floor.

Competition- Plants, animals, and insects all compete for limited resources in the park. This can cause organisms to fight for things such as food in order to survive. Based on the competitive exclusion principle, which states that two organisms which share the same niche cannot coexist in the same place, one of the species must either die or adapt. For example, fox and raccoon both both eat wild mice, but there are a limited number of mice in the ecosystem. These are both examples of predator-prey relationships and if both populations eat the mice, then there will not be enough mice left to sustain the needs of the fox and raccoon. One species might gain an advantage; fox are quicker, which allows them to catch more mice. This forces the raccoon population to either die out or to adapt; they may start to feed more on squirrels or insects instead of mice. These adaptations are all dependent on how many mice, fox, and raccoon live in a given area, which is their density.

Predation- Predation occurs when one organism feeds on another organism. Increases or decreases in prey population size can increase or decrease the predator population size, or vise versa. These changes can travel up or down the food chain to affect every organism in the ecosystem. Another example of a predator-prey relationship would be bear and rainbow trout. If food resources, such as insects, became more available to the trout, this would cause the bear population to increase because bear eat trout. On the other hand, if there was less food available to the trout, their population would decrease and, thus, the bear would have less food to eat and would also die. The bear might also be forced to feed on another prey, such as deer, which would decrease the deer population. Therefore, the food chain is also dependent on the density of the population.